recant
withdraw
reciprocate
to respond to an action by doing the same thing back to someone
reconcile
to bring opposing people or things back together
Register
official list or record, to become aware of or record
relevant/irrelevant
connected/unconnected to the topic at hand
renounce
to give up
replenish
to refill; resupply
resilient
capable of quickly recovering from difficulty
resurgence
the act of rising again in life or activity
retrospect
hindsight; looking back
revelation
something that is revealed and thus made known
rudimentary
limited to basic principals; elementary